Endoluminal device having enhanced affixation characteristics

ABSTRACT

An endoluminal device for affixation to a wall of a body lumen having a neck region defined by a relatively narrow width and a shoulder region that diverges from the neck region to a relatively wider width. The device comprises a shoulder portion, which may be part of a bulbous portion, having a diameter profile that conforms to the shoulder region, and, in some embodiments, a plurality of affixation members in an area of the device that typically extends from a distal end of the device through the shoulder portion. In one embodiment, the device comprises an endograft for repair of an aneurysm, such as an abdominal aortic aneurysm (AAA). Methods of using the endograft to inhibit continued diametric expansion of the aneurysm and to inhibit endoleak formation and migration of the endograft are also described.

FIELD OF THE INVENTION

[0001] This invention relates generally to endoluminal devices,particularly stents and grafts for placement in an area of a body lumenthat has been weakened by damage or disease, such as an aneurysm of theabdominal aorta, and more particularly to devices having characteristicsthat enhance affixation of the devices to the body lumen.

BACKGROUND OF THE INVENTION

[0002] Medical devices for placement in a human or other animal body arewell known in the art. One class of medical devices comprisesendoluminal devices such as stents, stent-grafts, filters, coils,occlusion baskets, valves, and the like. A stent is an elongated deviceused to support an intraluminal wall. In the case of a stenosis, a stentprovides an unobstructed conduit through a body lumen in the area of thestenosis. Such a stent may also have a prosthetic graft layer of fabricor covering lining the inside and/or outside thereof. A covered stent iscommonly referred to in the art as an intraluminal prosthesis, anendoluminal or endovascular graft (EVG), a stent-graft, or endograft.

[0003] An endograft may be used, for example, to treat a vascularaneurysm by removing the pressure on a weakened part of an artery so asto reduce the risk of rupture. Typically, an endograft is implanted in ablood vessel at the site of a stenosis or aneurysm endoluminally, i.e.by so-called “minimally invasive techniques” in which the endograft,typically restrained in a radially compressed configuration by a sheath,crocheted or knit web, or catheter, is delivered by a stent deliverysystem or “introducer” to the site where it is required. The introducermay enter the body from an access location outside the body, such asthrough the patient's skin, or by a “cut down” technique in which theentry blood vessel is exposed by minor surgical means. The term“proximal” as used herein refers to portions of the stent or deliverysystem relatively closer to the end outside of the body, whereas theterm “distal” is used to refer to portions relatively closer to the endinside the body.

[0004] After the introducer is advanced into the body lumen to theendograft deployment location, the introducer is manipulated to causethe endograft to be deployed from its constrained configuration,whereupon the stent is expanded to a predetermined diameter at thedeployment location, and the introducer is withdrawn. Stent expansion istypically effected by spring elasticity, balloon expansion, and/or bythe self-expansion of a thermally or stress-induced return of a memorymaterial to a pre-conditioned expanded configuration.

[0005] Among the many applications for endografts is that of deploymentin lumen for repair of an aneurysm, such as an abdominal aortic aneurysm(AAA). An AAA is an area of increased aortic diameter that generallyextends from just below the renal arteries to the aortic bifurcation.AAA generally results from deterioration of the arterial wall, causing adecrease in the structural and elastic properties of the artery. Inaddition to a loss of elasticity, this deterioration also causes a slowand continuous dilation of the lumen.

[0006] The standard surgical repair of AAA is an extensive and invasiveprocedure typically requiring a weeklong hospital stay and an extendedrecovery period. To avoid the complications of the surgical procedure,practitioners commonly resort to a minimally invasive procedure usingendoluminal endograft to reinforce the weakened vessel wall, asmentioned above. At the site of the aneurysm, the practitioner deploysthe endograft, anchoring it above and below the aneurysm to relativelyhealthy tissue. The anchored endograft diverts blood flow away from theweakened arterial wall, minimizing the exposure of the aneurysm to highpressure.

[0007] Intraluminal stents for repairing a damaged or diseased artery orto be used in conjunction with a graft for delivery to an area of a bodylumen that has been weakened by disease or damaged, such as an aneurysmof the abdominal aorta, are well established in the art of medicalscience. Intraluminal stents having barbs, hooks, or other affixationmeans to secure the stents to the wall of the lumen in which they are tobe deployed are also well known in the art. Referring now to FIG. 1,there is shown an exemplary embodiment of an endograft 10 comprising astent 11 having a graft lining 12 and a plurality of hooks 13 foraffixation to the wall 14 of aorta 15 afflicted with an aneurysm. Theaffixation means, such as hooks 13, are important because subsequentmovement (or “migration”) of the endograft may cause the aneurysm tobecome exposed to blood pressure. In particular, if the device migratesproximally over time in the direction of arrow A, as shown in FIG. 1, aleak at distal end 16 of the device, sometimes referred to in the art asa “Type I endoleak,” may cause blood to flow undesirably to theaneurysm.

[0008] Even with standard affixation means, however, continuedprogression of the aneurysm may lead to diametric expansion of theaneurysm along arrows B as shown in FIG. 1. In particular, in AAAapplications, the portion of the aneurysm closest to the renal arteries17, referred to herein as the “renal neck” 18, may undergo thisdiametric expansion. The “renal neck” is often referred to bypractitioners as the “proximal neck” where the term “proximal” meansanatomically as closer to the heart. Because this application does notuse anatomical definitions of “proximal” and “distal,” the term “renalneck” is used herein avoid confusion. This diametric expansion of therenal neck may result in ineffective engagement of one or more of thehooks around the circumference of the renal neck, and may lead to a TypeI endoleak, as illustrated by separation 20 between aorta wall 14 andendograft 10 in FIG. 2, and/or distal migration of the endograft.

[0009] Accordingly, it can be seen that while the art has advanced theuse of barbs to minimize migration of a deployed stent-graft, even theuse of such barbs may not be sufficient to prevent endoleaks.Accordingly, there is still a need in the art for endograft designshaving enhanced affixation characteristics.

SUMMARY OF THE INVENTION

[0010] The foregoing general description and subsequent detaileddescription are representative, not restrictive, of the invention.

[0011] One aspect of the invention comprises an endoluminal device foraffixation to a wall of a body lumen having a neck region defined by arelatively narrow width and a shoulder region that diverges from theneck region to a relatively wider width. The device comprises a shoulderportion, having a diameter profile that conforms to the shoulder region,such as a shoulder portion having a bulbous geometry, for deployment inthe shoulder region. At least part of the shoulder region may furthercomprise a plurality of affixation members, including but not limited tohooks, barbs, or other members that project radially outward from thedevice. In one embodiment, the device comprises an endograft comprisinga stent that is at least partially covered or lined with a graftmaterial, for example, an endograft adapted to repair an aneurysm suchas an AAA. The endoluminal device typically comprises a compressedconfiguration and a radially expanded configuration, and in at least oneembodiment, the device neck has a first radial self-expansion force andthe bulbous portion has a second radial self-expansion force less thanthe first radial expansion force.

[0012] Another aspect of the invention comprises an endograft for repairof an AAA. The endograft comprises a stent at least partially lined orcovered by a graft material and having enhanced affixationcharacteristics, the endograft having a first end comprising a distalneck having a first diameter and a shoulder portion located adjacent thedistal neck and having a diverging then converging diameter greater thanthe first diameter. At least the distal neck and part of the shoulderportion may comprise a plurality of affixation members that projectradially outward from the device for affixation to the lumen wall of theAAA. The plurality of affixation members are typically disposed in anarea of the endograft that extends axially from the distal end of theendograft to at least an intermediate location in the bulbous portion,and in one embodiment, to a maximum diameter portion of the bulbousportion. In one embodiment, the endograft may further comprise aproximal end comprising at least one proximal neck having a seconddiameter and a second bulbous portion located distally of the proximalneck and having a distally diverging then converging diameter greaterthan the second diameter, at least the proximal neck and part of thesecond bulbous portion comprising a plurality of affixation members thatproject radially outward from the device for affixation to the lumenwall of the AAA.

[0013] Yet another aspect of the invention comprises a method forinhibiting diametric expansion of an aneurysm. The method comprisesdeploying an endograft in the aneurysm, the endograft having anendograft neck with a diameter approximately equal to the width of theaneurysm neck region and a bulbous portion having at least a distalportion adapted to match a proximally diverging width of the shoulderregion of the aneurysm, wherein the endograft neck and the distalportion of the bulbous portion comprise a plurality of affixationmembers for affixing to the lumen wall of the aneurysm.

[0014] Still another aspect of the invention comprises a method ofinhibiting endoleak formation and migration of an endograft deployed ina lumen, the lumen having a lumen wall, a lumen neck region having alumen neck width, and a lumen shoulder region proximal the lumen neckregion having a proximally diverging width greater than the lumen neckregion width. The method comprises providing the endograft with anendograft neck having a diameter approximately equal to the lumen neckregion diameter and a shoulder portion adapted to match the proximallydiverging diameter of the lumen shoulder region. The method may furthercomprise providing the endograft neck and the distal portion of theshoulder portion with a plurality of affixation members for affixing tothe lumen wall. The shoulder portion may be provided as part of abulbous portion.

[0015] An additional aspect of the invention comprises a method ofrepairing a body lumen having a lumen wall, a lumen neck region having alumen neck width, and a lumen shoulder region proximal the lumen neckregion having a proximally diverging width greater than the lumen neckregion width. The method comprises the steps of providing an endografthaving the shoulder portion, bulbous portion and affixation members asdescribed herein and having an expanded configuration and a compressedconfiguration; constraining the endograft in the compressedconfiguration for introduction into the body lumen; advancing theendograft to a deployment location aligned with the lumen neck regionand lumen shoulder region; and deploying the endograft so that one ormore of the affixation members attached to the endograft neck affix tothe lumen neck region and one or more of the affixation members attachedto the shoulder portion affix to at least a portion of the lumenshoulder region. The method may be used for repairing an aneurysm, suchas an AAA.

[0016] Where the endograft comprises a self-expanding stent having atleast a partial covering or lining of a graft material, the method maycomprise the stent exerting a radial expansion force against the lumenwall in the neck region that is greater than the radial expansion forceexerted by the bulbous portion. Where the endograft comprises a modulardevice having at least two modular components—a first modular componentcomprising a distal bulbous region and one or more second modularcomponents each comprising a proximal bulbous region—the method maycomprise deploying the first modular component and deploying the one ormore second modular components to mate with the first modular component.

BRIEF DESCRIPTION OF THE DRAWING

[0017] The invention is best understood when the following detaileddescription is read with reference to the attached drawing, in which:

[0018]FIG. 1 is an illustration of a cross-section of an abdominalaortic aneurysm (AAA), showing a plan view of an exemplary endograft ofthe prior art deployed therein;

[0019]FIG. 2 is a cross-sectional illustration of the endograft andaorta of FIG. 1 taken across line 2-2, illustrating a Type I endoleak;

[0020]FIG. 3 is a plan view of an exemplary endoluminal device having adistal bulbous portion deployed in renal neck and shoulder region of anAAA shown in cross-section;

[0021]FIG. 4 is a plan view of another exemplary endoluminal device ofthe present invention comprising a plurality of proximal bulbousportions deployed in the iliac neck and shoulder regions of an AAA shownin cross-section; and

[0022]FIG. 5 is a flowchart depicting an exemplary method of theinvention.

DETAILED DESCRIPTION OF THE INVENTION

[0023] The invention will next be illustrated with reference to thefigures wherein the same numbers indicate similar elements in allfigures. Such figures are intended to be illustrative rather thanlimiting and are included herewith to facilitate the explanation of theapparatus of the present invention.

[0024] Referring now to FIG. 3, there is shown an endoluminal device 30for affixation to the lumen wall 32 of diseased aorta 34 that isafflicted with an aneurysm. Diseased aorta 34 comprises a neck region 36defined by a relatively narrow width w₁, and a shoulder region 38 thatdiverges from the neck region to a relatively wider width greater thanw₁. Device 30 comprises a device neck 40 (also referred to herein as“distal neck” in reference to FIG. 3 and “endograft neck”) having arelatively constant diameter d₁ along its length and a bulbous portion41 having a proximally diverging then converging diameter greater thandiameter d₁ along its length. It should be noted that although the term“diameter” is used herein, the invention is not limited to embodimentshaving a perfectly circular cross-section. Thus, the term “diameter”should be interpreted to refer to the “effective diameter” ofnon-circular cross-sections, meaning an average of the width across thedevice at a given axial plane. At least the distal, shoulder portion 46of bulbous portion 41 conforms to the contour of shoulder region 38. Aplurality of affrxation members 42 are disposed throughout an affixationarea 44 that spans proximally from the distal or upstream end 16 of thedevice, through neck 40 and through at least distal portion 46 ofbulbous portion, preferably to an intermediate location in the bulbousportion, such as to maximum diameter portion 47 having a diameter d₂.The affixation members typically comprise hooks, barbs, other membersthat project radially outward from the device, or any type of memberknown in the art for affixing an endoluminal device to a lumen wall.

[0025] Endoluminal device 30 as shown in FIG. 3 is an endograftcomprising a stent 50 and a graft 52, which is shown in FIG. 3 as alining on the radial inside surface of the stent. As is well known inthe art, the graft material may also be provided as a covering on theradial outside surface of the stent. In some embodiments, the stent maycomprise a self-expanding stent as is known in the art. Because of theweakened structure of the diametrically expanded walls of the aneurysm,in some embodiments it may be particularly advantageous forself-expanding stents to exert a lesser radial self-expansion force atbulbous portion 41 than at distal neck 40. This difference in radialself-expansion force between the two areas may be important to minimizethe risk of rupture during device placement.

[0026] The difference in radial self-expansion force may be provided byproviding different stent geometries or stent architectures in thedifferent portions of the stent. Methods of providing differentproperties in different portions of a stent are described in U.S. patentapplication Ser. No. 09/442,192 (“the '192 application”), filed Nov. 16,1999, titled ENDOLUMINAL STENT HAVING A MATCHED STIFFNESS REGION AND/ORA STIFFNESS GRADIENT AND METHODS FOR PROVIDING STENT KINK RESISTANCE andin U.S. patent application Ser. No. 09/442,165 (“the '165 application”),filed Nov. 16, 1999, titled MULTI-SECTIONAL FILAMENTARY ENDOLUMINALSTENT, both of which are incorporated herein by reference. For example,as detailed in the '192 application, different stent geometries and/orarchitectures may be used to provide portions having different radialstrength, which in turn exert different amounts of radial force.Specifically, a wound stent architecture, such as the hexagonal cellarchitecture shown in FIG. 3, may be provided in neck 40 and a braidedarchitecture may be provided in bulbous portion 41, in accordance withthe hybrid wound/braided stents discussed generally in the '165application. Exemplary structures and methods for providing affixationmembers on stents are described in U.S. patent application Ser. No.10/153,351, filed on May 22, 2002, by James Weldon and Zarouhi Minasianand titled ENDOLUMINAL DEVICE HAVING BARB ASSEMBLY AND METHOD OF USINGSAME, incorporated herein by reference. In particular, the '351application describes structures for providing affixation members forbraided portions of hybrid wound/braided stents and at the intersectionof a braided portion and a wound portion.

[0027]FIG. 3 shows only a distal portion of endograft 30, which maycomprise a trunk section of a bifurcated device that has two proximallegs for repairing an abdominal aortic aneurysm (AAA). The invention isnot limited, however, to any particular type of device or application.For example, the proximal portion of endograft 30 (not shown) may notbranch into any legs, may have more than two legs or branches, may be amodular design comprising one leg and female member for receiving asecond leg, or may have any design known in the art. Furthermore, abulbous portion with affixation members may be provided as part of anytype of endoluminal device in addition to use with endografts, such asbut not limited to stents without a graft covering or lining, filters,coils, occlusion baskets, valves, and the like. Although endograft 30 isshown repairing an AAA, an endograft having a bulbous portion withaffixation members may also be beneficial for repairing a thoracicaortic aneurysm (TAA) or an aneurysm in any location in the body. Theuse of a bulbous portion with affixation members may also provebeneficial in non-aneurysmal applications having a geometry that canbenefit from the bulbous geometry.

[0028] Deploying an endograft as described herein in an aneurysm mayadvantageously inhibit diametric expansion of the aneurysm by radiallyfixturing the marginally diseased tissue in the shoulder region of theaneurysm. By preventing or at least delaying continued diametricexpansion of the shoulder region, the endograft may thereby inhibitprogression of the disease and better prevent a rupture of the aneurysm.The increase in length of endograft engagement along the aortic wallalso inhibits endoleak formation by providing improved migrationresistance and better sealing as compared to endografts lacking thebulbous portion. Furthermore, the increased affixation area provides alonger path for Type 1 endoleaks to travel prior to entering andsubsequently repressurizing the aneurysmal sac. The longer pathway thusincreases the chance of spontaneous endoleak stagnation and thrombosiswhich may repair the endoleak without need for surgical intervention orother remedial measures. The logic followed by the present invention isthat it is more beneficial to minimize the risk of subsequent aneurysmalrupture than to restore the original cylindrical aortic geometry. Theexertion of less radial force by bulbous portion 41 of endograft 30 thanby neck 40 is consistent with this logic, because the lesser radialforce minimizes the risk that the radial force exerted by the stentitself might rupture the aneurysm.

[0029] The advantages described above with respect to the embodimentshown in FIG. 3 may also be enjoyed in other locations. Referring now toFIG. 4, there is shown another embodiment of the present inventioncomprising iliac leg portions 60 and 61 of an endograft 62, each havingproximal bulbous portions 64 and a plurality of affixation members 66.Bulbous portions 64 are adapted for deployment in shoulder regions 67located distally of iliac necks 68 of iliac arteries 70 and 71 at theproximal end of an aneurysm. Like the embodiment shown in FIG. 3, theuse of such an embodiment may prevent or delay continued diametricexpansion of shoulder region 67, thereby inhibiting progression ofaneurysmal disease, and may also inhibit endoleak formation by providingimproved migration resistance and better sealing as compared toendografts lacking the bulbous portion.

[0030] Leg portions 60 and 61 may be part of a modular or non-modularAAA prosthesis comprising a distal bulbous portion 41 as depicted inFIG. 3, or may be part of a modular or non-modular AAA prosthesiscomprising a standard, non-bulbous trunk portion known in the art. Theconnections between leg portions 60 and 61 and prosthesis 30 maycomprise any connection for modular or non-modular prostheses known inthe art, including embodiments in which distal bulbous portion 41 andone of proximal bulbous portions leg portions 60 and 61 are part of asingle modular component, and the other leg comprises a mating modularcomponent. Embodiments in which both leg portions are modular componentsor both legs are integral components may also be provided. Leg portions60 and 61 may be deployed by any method known in the art.

[0031] Although depicted as two leg members 60 and 61 for deployment iniliac arteries 70 and 71, respectively, it should be understood that aprosthesis may comprise more than two dependent members of any type, andthat such a prosthesis having dependent members may be adapted fordeployment in any type of body lumen. Furthermore, although both legmembers are shown with bulbous portions in FIG. 4, embodiments may alsobe provided in which less than all of the multiple dependent membershave bulbous portions.

[0032] Thus, the endograft embodiments of the present invention may beused for performing a method of repairing a body lumen, as depicted inthe flowchart shown in FIG. 5. The method first comprises step 100 ofproviding an endograft having an expanded configuration as shown in FIG.3 and a compressed configuration (not shown), similar to the compressedconfiguration known in the art for any endoluminal device. In theexpanded configuration, the endograft has a neck 40 with diameter d₁approximately equal to the lumen neck region width w₁ and a bulbousportion 41 having at least a distal, shoulder portion 46 adapted tomatch the diverging width of lumen shoulder region 38. Endograft 30comprises a plurality of affixation members 42 for affixing to lumenwall 32, the affixation members disposed along an axial portion 44 ofendograft 30 including at least neck 40 and distal portion 46 of bulbousportion 41. The method then comprises step 110 of constraining theendograft in its compressed configuration for introduction into the bodylumen. Next, in step 120, the compressed and constrained endograft 30 isadvanced to a deployment location aligned with the lumen neck region andlumen shoulder region, such as the region shown in FIG. 3. Finally, instep 130, endograft 30 is deployed so that one or more of affixationmembers 42 in endograft neck 40 affix to lumen neck region 36 and one ormore of the affixation members in bulbous portion 41 affix to at least aportion of lumen shoulder region 38. As shown in FIG. 3, where stent 50is a self-expanding stent, the stent in the area of neck 40 exerts aradial expansion force that is greater than the radial expansion forceexerted in the area of bulbous portion 41.

[0033] For a modular endograft with multiple bulbous regions, such as anendograft comprising bulbous portion 41 at its distal end, as shown inFIG. 3, and iliac leg portions 60 and 61 at its proximal end, as shownin FIG. 4, it may be desirable to first deploy bulbous portion 41 asdescribed above, and then reverse-deploy the leg portions to assuredesired placement of the bulbous portions 64. Exemplary reversedeployment methods are described generally in U.S. application Ser. No.10/080,791, filed Feb. 22, 2002, by Haverkost et al., titled METHOD ANDSYSTEM FOR DEPLOYING MULTI-PART ENDOLUMINAL DEVICES, incorporated hereinby reference.

[0034] The devices as well as any graft linings or coatings used withthe devices of the present invention may comprise any suitable materialsof construction known in the art, including any type of surfacemodification known in the art. For example, it may be desirable toprovide the device with a coating of a biologically or pharmacologicallyactive substance for enhancing the effectiveness of the devicegenerally, or of the shoulder or bulbous portion specifically. The term“biologically or pharmacologically active substance” refers to anysubstance, whether synthetic or natural, that has a pharmacological,chemical, or biological effect on the body or a portion thereof.Suitable biologically or pharmacologically active materials that can beused in this invention include without limitation glucocorticoids (e.g.dexamethasone, betamethasone), antithrombotic agents such as heparin,cell growth inhibitors, hirudin, angiopeptin, aspirin, growth factorssuch as VEGF, antisense agents, anti-cancer agents, anti-proliferativeagents, oligonucleotides, antibiotics, and, more generally, antiplateletagents, anti-coagulant agents, antimitotic agents, antioxidants,antimetabolite agents, and anti-inflammatory agents may be used.Antiplatelet agents can include drugs such as aspirin and dipyridamole.Aspirin is classified as an analgesic, antipyretic, anti-inflammatoryand antiplatelet drug. Dipyridamole is a drug similar to aspirin in thatit has anti-platelet characteristics. Dipyridamole is also classified asa coronary vasodilator. Anticoagulant agents may include drugs such asheparin, protamine, hirudin and tick anticoagulant protein. Anti-canceragents may include drugs such as taxol and its analogs or derivatives.Taxol is also classified as a cell-growth inhibitor. Antioxidant agentsmay include probucol. Anti-proliferative agents may include drugs suchas amlodipine and doxazosin. Antimitotic agents and antimetaboliteagents may include drugs such as methotrexate, azathioprine,vincristine, vinblastine, 5-fluorouracil, adriamycin and mutamycin.Antibiotic agents can include penicillin, cefoxitin, oxacillin,tobramycin, and gentamicin. Suitable antioxidants include probucol.Also, genes or nucleic acids, or portions thereof may be used. Suchgenes or nucleic acids can first be packaged in liposomes ornanoparticles. Furthermore, collagen-synthesis inhibitors, such astranilast, may be used.

[0035] Additional biologically or pharmacologically active substancesand carriers for these substances are listed in U.S. Pat. Nos.6,364,856; No. 6,358,556; and No. 6,258,121; all of which areincorporated herein by reference. In addition to disclosing additionalactive substances, these patent references disclose polymer materialsimpregnated with active substances for use as coatings on the outside ofmedical devices to provide controlled delivery of the active substances.Devices of the present invention may also comprise such impregnatedpolymer materials.

[0036] Although the aorta illustrated in FIG. 3 has a generally regularshape, aneurysms with irregular shapes are not uncommon. Therefore, itmay be additionally desirable to provide the device with one or moreportions, particularly the shoulder or bulbous portion, with the abilityto conform to an irregular shape. This may be accomplished using aballoon-expandable stent framework having plastically-deformablematerials of construction, such as but not limited to gold, platinum,tantalum, titanium, stainless steel, tungsten, a cobalt alloy, a nickelor titanium alloy, such as a plastically deformable grade of nitinol ordeformable core nitinol composite, or a combination of any of the above.A combination self-expanding, balloon-expandable stent framework mayalso be used, comprising a combination of superelastic and plasticallydeformable materials, such as is described, for example, in U.S. patentapplication Ser. No. 09/702,226, to Steven E. Walak, titled COMBINATIONSELF-EXPANDABLE, BALLOON-EXPANDABLE ENDOLUMINAL DEVICE, filed Oct. 31,2000, and incorporated herein by reference. Methods of using suchdevices include deploying the device initially by self-expansion,followed by modeling the plastically deformable sections to conform tothe lumen geometry using an inflatablee balloon or other modeling device

[0037] Although the bulbous portions disclosed in the present inventionare shown at or near the ends of the devices, it should be understoodthat a bulbous portion may be provided at any location on a device.Furthermore, although a bulbous configuration has been generallydescribed herein, it should be understood that the importantcharacteristic of the device is that the shoulder portion have adiameter profile that conforms to the contour of the shoulder region ofthe lumen. By “diameter profile that conforms to the contour” it ismeant that if the lumen shoulder region diameter diverges from a neckregion having a first diameter to a relatively wider second diameteralong a given length with a given slope, the shoulder portion of thedevice similarly diverges from approximately the first diameter toapproximately the second diameter along approximately the same givenlength with approximately the same given slope. Thus, if lines plottingthe diameter versus length were graphed for the shoulder region of thedevice and the shoulder region of the lumen, the line corresponding tothe shoulder portion of the device would have a similar slope the linefor the shoulder region of the lumen. While it is important thatshoulder portion 46 of device 30 shown in FIG. 3 has a configurationthat conforms to shoulder region 38 of the lumen, the device proximal ofshoulder portion may have any configuration, such as a configurationwith a tapering diameter or even a step-change back to diameter d₁rather than the bulbous configuration shown.

[0038] Finally, providing a bulbous portion or other defined shoulderportion having a diameter profile that conforms to the contour of theshoulder region of the lumen in which the device is implanted isadvantageous both by itself and in conjunction with providing affixationmembers in the bulbous or shoulder portion. Although the figures shownherein depict bulbous or shoulder portions with affixation members, itshould be recognized that devices having such portions withoutaffixation members may also be provided.

[0039] Although illustrated and described herein with reference tocertain specific embodiments, the present invention is nevertheless notintended to be limited to the details shown. Rather, variousmodifications may be made in the details within the scope and range ofequivalents of the claims and without departing from the spirit of theinvention. In particular, for example, although some embodiments havebeen described herein having elements labeled with “distal” or“proximal” directional descriptors, it should be understood that oneequivalent embodiment may comprise the same elements with thedirectional descriptors reversed.

What is claimed is:
 1. An endoluminal device for affixation to a wall of a body lumen, the body lumen having a neck region defined by a relatively narrow width and a shoulder region that diverges from the neck region to a relatively wider width, the device comprising a shoulder portion having a device diameter profile that conforms to a lumen diameter profile of the shoulder region for deployment in the shoulder region.
 2. The device of claim 1, wherein the shoulder portion comprises part of a bulbous portion.
 3. The endoluminal device of claim 2, wherein the device comprises a device neck located adjacent the bulbous portion, the device neck having a first diameter, and the bulbous portion having a length characterized by a diverging and converging diameter greater than the first diameter along the bulbous portion length.
 4. The endoluminal device of claim 3, wherein the device comprises a compressed configuration and a radially expanded configuration, the device neck having a first radial self-expansion force and the shoulder portion having a second radial self-expansion force less than the first radial expansion force.
 5. The device of claim 2, wherein the bulbous portion of the device comprises a stent having at least one superelastic section and at least one plastically deformable section.
 6. The device of claim 1 further comprising a plurality of affixation members at least on part of the shoulder portion.
 7. The endoluminal device of claim 6, wherein the affixation members comprise hooks, barbs, or other members that project radially outward from the device.
 8. The endoluminal device of claim 6, wherein the device has a distal end adapted to be positioned in an upstream portion of the lumen and the plurality of affixation members are disposed in an area of the device extending proximally from the distal end of the device through the shoulder portion.
 9. The endograft of claim 8, wherein the area in which the plurality of affixation members are disposed extends axially to a maximum diameter portion of the shoulder portion.
 10. The endoluminal device of claim 1, wherein the device comprises a stent.
 11. The device of claim 10, wherein the stent comprises at least one superelastic section and at least one plastically deformable section.
 12. The device of claim 1, wherein the shoulder portion of the device comprises a stent having at least one superelastic section and at least one plastically deformable section.
 13. The endoluminal device of claim 1, wherein the device comprises an endograft comprising a stent that is at least partially covered or lined with a graft material.
 14. The endoluminal device of claim 13, wherein the endograft is adapted to repair an aneurysm.
 15. The endoluminal device of claim 14, wherein the endograft is adapted to repair an abdominal aortic aneurysm (AAA).
 16. The endoluminal device of claim 15, wherein the neck region includes a renal neck at a distal end of the aneurysm and the shoulder portion is positioned proximal the renal neck at the shoulder region.
 17. The endoluminal device of claim 15, wherein the neck region includes an iliac neck at a proximal end of the aneurysm and the shoulder portion is positioned distally of the iliac neck.
 18. An endoluminal device adapted to repair an abdominal aortic aneurysm (AAA) for affixation to a wall of a body lumen, the body lumen having a renal neck region, defined by a relatively narrow width, and a renal shoulder region that diverges from the renal neck region at a distal end of the aneurysm and an iliac neck region, defined by a relatively narrow width, and an iliac shoulder region that diverges from the iliac neck region at a proximal end of the aneurysm, the device comprising a distal shoulder portion having a diameter profile that conforms to the renal shoulder region for deployment in the renal shoulder region; and one or more proximal shoulder portions each for deployment in the iliac shoulder region, each proximal shoulder portion having a diameter profile that conforms to the corresponding iliac shoulder region.
 19. The device of claim 18 further comprising a plurality of affixation members at least on part of the distal shoulder portion and on part of the one or more proximal shoulder portions.
 20. The device of claim 29 wherein the distal shoulder portion is part of a distal bulbous portion and each of the one or more proximal shoulder portions are part of a corresponding proximal bulbous portion.
 21. The endoluminal device of claim 18, wherein the distal shoulder portion and the one or more proximal shoulder portions comprise a non-modular device.
 22. The endoluminal device of claim 18, wherein the distal shoulder portion and the one or more proximal shoulder portions comprise a modular device.
 23. The endoluminal device of claim 22, wherein a first modular component comprises the distal shoulder portion and a first proximal shoulder portion, and a second modular component comprises a second proximal shoulder portion.
 24. An endograft for repair of an abdominal aortic aneurysm (AAA) having a lumen wall, the endograft comprising a stent at least partially lined or covered by a graft material and having a distal end comprising a distal neck having a first diameter and a first bulbous portion located proximally of the distal neck and having a proximally diverging then converging diameter greater than the first diameter, at least the distal neck and part of the first bulbous portion comprising a plurality of affixation members that project radially outward from the device for affixation to the lumen wall of the AAA.
 25. The endograft of claim 24, wherein the plurality of affixation members are disposed in an area that extends axially from a distal end of the endograft to at least an intermediate location in the first bulbous portion.
 26. The endograft of claim 25, wherein the area in which the plurality of affixation members are disposed extends axially to a maximum diameter portion of the first bulbous portion.
 27. The endograft of claim 24 having a compressed configuration and a radially expanded configuration, the device neck having a first radial self-expansion force and the first bulbous portion having a second radial self-expansion force less than the first radial self-expansion force.
 28. The endograft of claim 24 further comprising a proximal end comprising at least one proximal neck having a second diameter and an additional corresponding bulbous portion located distally of the proximal neck and having a distally diverging then converging diameter greater than the second diameter, at least the proximal neck and part of the additional corresponding bulbous portion comprising a plurality of affixation members that project radially outward from the device for affixation to the lumen wall of the AAA.
 29. The endograft of claim 28 comprising two proximal necks and two additional corresponding bulbous portions, each proximal neck and additional corresponding bulbous portion for deployment adjacent an iliac neck region of the AAA.
 30. The endograft of claim 28, wherein the distal neck and first bulbous portion comprise a first modular component and the proximal neck and additional corresponding bulbous portion comprises a second modular component.
 31. The endograft of claim 29, wherein the distal neck and first bulbous portion comprise a first modular component, and each proximal neck and additional corresponding bulbous portion comprise additional modular components.
 32. The endograft of claim 29, wherein the distal neck, first bulbous portion, one proximal neck, and one additional corresponding bulbous portion comprise a first modular component, and another proximal neck and additional corresponding bulbous portion comprise a second modular component.
 33. A method of inhibiting diametric expansion of an aneurysm having a lumen wall, the aneurysm having an aneurysm neck region at one end having a width and a shoulder region adjacent the neck region having a diverging width greater than the width of the aneurysm neck region, the method comprising deploying an endograft in the aneurysm, the endograft having an endograft neck with a diameter approximately equal to the width of the aneurysm neck region and a shoulder portion having a device diameter profile that conforms to a lumen diameter profile of the shoulder region of the aneurysm, the endograft neck and the shoulder portion comprising a plurality of affixation members for affixing to the lumen wall of the aneurysm.
 34. A method of inhibiting endoleak formation and migration of an endograft deployed in a lumen having a lumen wall, a lumen neck region having a lumen neck width, and a lumen shoulder region adjacent the lumen neck region having a diverging width greater than the lumen neck region width, the method comprising: providing the endograft with an endograft neck having a diameter approximately equal to the lumen neck region diameter and a shoulder portion adapted to match the diverging width of the lumen shoulder region.
 35. The method of claim 34 further comprising providing the endograft neck and the shoulder portion with a plurality of affixation members for affixing to the lumen wall.
 36. The method of claim 34 further comprising providing the shoulder portion as part of a bulbous portion.
 37. The method of claim 35 further comprising providing the shoulder portion as part of a bulbous portion.
 38. A method of repairing a body lumen having a lumen wall, a lumen neck region having a lumen neck width, and a lumen shoulder region proximal the lumen neck region having a diverging width greater than the lumen neck region width, the method comprising the steps of: (a) providing an endograft having an expanded configuration and a compressed configuration, the endograft comprising in the expanded configuration an endograft neck with a diameter approximately equal to the lumen neck region width and a bulbous portion having a shoulder portion adapted to match the diverging width of the lumen shoulder region; and the endograft comprising a plurality of affixation members for affixing to the lumen wall, the affixation members disposed along an axial region of the endograft including at least the endograft neck and the shoulder portion of the bulbous portion; (b) constraining the endograft in the compressed configuration for introduction into the body lumen; (c) advancing the endograft to a deployment location; and (d) deploying the endograft so that the endograft shoulder portion is aligned with the lumen shoulder region and one or more of the affixation members in the endograft neck affix to the lumen neck region and one or more of the affixation members in the endograft shoulder portion affix to at least a portion of the lumen shoulder region.
 39. The method of claim 38, wherein the method comprises repairing an aneurysm.
 40. The method of claim 38, wherein the method comprises repairing an abdominal aortic aneurysm.
 41. The method of claim 39, wherein the endograft comprises a self-expanding stent having at least a partial covering or lining of a graft material, the step of deploying the endograft comprising releasing the endograft from a radial constraint that confines it in the compressed configuration so that the self-expanding stent self-expands from the compressed configuration to the expanded configuration.
 42. The method of claim 41, wherein, after deploying the stent, the stent exerts a radial expansion force against the lumen wall, wherein the radial expansion force exerted by the endograft neck is greater than the radial expansion force exerted by the bulbous portion.
 43. The method of claim 41, wherein the endograft comprises a combination self-expanding/plastically-deformable stent and the step of deploying the endograft further comprising, after the self-expansion of the stent, modeling the stent the conform the stent to the lumen wall.
 44. A method of repairing an abdominal aortic aneurysm (AAA) in a body lumen having a lumen wall, the body lumen having, at a distal end of the AAA, a renal neck region, defined by a relatively narrow width, and a renal shoulder region that diverges from the renal neck region; and, at a proximal end of the AAA, one or more iliac neck regions defined by a relatively narrow width, and one or more iliac shoulder regions, each of which diverges from the corresponding iliac neck region, the method comprising the steps of: (a) providing an endograft having an expanded configuration and a compressed configuration, the endograft comprising a modular device having a first modular component comprising a distal bulbous region and one or more additional modular components each comprising a proximal bulbous region, wherein, in the expanded configuration, the endograft comprises (i) a first endograft neck with a diameter approximately equal to the renal neck region width with the distal bulbous portion having at least a shoulder portion adapted to match the diverging width of the renal shoulder region and (ii) an additional endograft neck with a diameter approximately equal to the iliac neck region width with the proximal bulbous portion having at least a shoulder portion adapted to match the diverging width of the iliac shoulder region; and the endograft comprises a plurality of affixation members for affixing to the lumen wall, the affixation members disposed along an axial region of the endograft including at least the first and additional endograft necks and the shoulder portion of the distal bulbous portion and the shoulder portion of the proximal bulbous portion; (b) constraining the endograft in the compressed configuration for introduction into the body lumen; (c) advancing the endograft to a deployment location; (d) deploying the first modular component of the endograft so that the shoulder portion of the distal bulbous portion is aligned with the renal shoulder region and one or more of the affixation members in the first endograft neck affix to the renal neck region and one or more of the affixation members in the distal bulbous portion affix to at least a portion of the renal shoulder region; and (e) then deploying the one or more additional modular components of the endograft so that the shoulder portion of each proximal bulbous portion is aligned with a corresponding iliac shoulder region and one or more of the affixation members in each additional endograft neck affix to the corresponding iliac neck region and one or more of the affixation members in each proximal bulbous portion affix to at least a portion of the corresponding iliac shoulder region, each of the one or more additional modular components mating with the first modular component such that a distal end of each additional modular component connects to a proximal end of the first modular component.
 44. The method of claim 43, comprising reverse-deploying the one or more additional modular components. 